Question Allowed avatar file extensions not working

Hey, been building my website and I'm testing it for errors atm.
One error I found and I can't fix is that when my friend tried to upload a .bmp image, it didn't work.
First of all, I added the bmp to the allowed images list, also added the corresponding MIME type image/bmp to the MIME list.
My friend tried to upload the file, and it said it was the wrong file extension and wasn't allowed.
It also displayed the allowed extensions (txt,rtf,pdf,zip,tar.gz,tgz,tar.bz2) from the normal files and not images.
Even after adding bmp to the allowed files list, he cannot upload bmp files, and the size shouldn't be a problem, it's set to 1mb and the image is way under.

Any ideas?
PS: I'm using the newest kuena with joomla 1.5, K2 and jcomments.

The MIME type for BMP files is image/x-ms-bmp, not image/bmp

Also, make sure your list of allowed file extensions is comma-separated. So gif,jpg,png,bmp and not gif,jpg,png.bmp

Yeah, I suspected the MIME (of course microsoft has to have their own name in everything they stick their nose into) was the problem since it didn't recognize the file as an image, and yes I can read, I didn't separate them with dots.
Anyway, I'll let my friend test it again, might as well disable the MIME thing all together, or are there any security risks by doing this?

very big security risks, yes. Changing the mime type to image/x-ms-bmp worked fine for me. Using image/bmp failed.

It;s worth nothing that it takes all of a minute to change a bmp to a jpg, and it makes it smaller too. The server just converts it to a jpg anyways after it's uploaded.

Yes I'm aware of that, however I'm just testing.
Also, using image/x-ms-bmp didn't work, still not able to upload bmp images.

Anyone?